Coax Feedline Attenuation Chart

All coaxial feedline cables exhibit loss. The type of feedline you choose can make a big difference on the the performance and range of your antenna system. A feedline should be chosen based on the length of the cable run and the frequency of the signal. Of course cost is also an important consideration. Balancing all these variables will help you in selecting a coax cable that will best suit your needs.

The attenuation chart lists the amount of loss in decibels (Db) per 100 feet for a given frequency. Loss values are a multiplier, so a 200 foot feedline run would have double the loss at a given frequency. Likewise a 50 foot run would have half the loss.

10 MHz 30 Mhz 50 Mhz 100 Mhz 150 MHz 220 MHz 450 MHz
RG-174 3.3 5.5 6.6 8.9 13 17.3 25
RG-316 2.1 4.2 5.6 7.9 9.6 11.9 17
RG-58 1.4 2.5 3.1 4.9 6.2 7.4 10.6
RG-8X 1.0 2.0 2.5 3.6 4.7 6.0 8.6
RG-8U/RG-213 0.6 1.2 1.6 2.2 2.8 3.5 5.2
Belden 9913 0.4 0.8 1.1 1.3 1.7 2.1 3.1
Belden 9914 0.4 0.8 1.1 1.4 1.7 2.1 3.1
LMR-400 0.4 0.8 0.9 1.2 1.5 1.8 2.7
1/2″ Superflex 0.3 .56 0.73 1.04 1.3 1.6 2.3

If you want the losses for a custom length of feed line or a line not listed in this chart, I recommend this calculator: